I have been trying to get my old Honda running again, but I have a fuel problem. I've cleaned the carb and replaced the fuel line and filter. If I hold the carb in my hand and turn the key on the float and needle valve work perfectly. Even if I turn I'd sideways to some degree, and if I continue turning it, it will begin to overfill as it should. I straighten it up and it stops. However once bolted up it only works as long as the engine is not running. It seems the vibration is enough to cause the float and valve to be forced open, like a fuel over pressure situation. It will quickly flood the engine and even flow fuel directly into it. The fuel pump doesn't shut off and you can hear it bog down as pressure rises. Is there supposed to be a pressure regulator, or cutoff switch? I haven't measured the pressure yet but it feels like about 15 psi when we need 1 to 2 psi. I mean it really sprays! I can't seem to find anything that limits the pressure, is it supposed to be internal to the pump? Any help you can give me would be greatly appreciated. I have spent a lot of time trying to figure it out, and I really love this machine. Also I'm fighting stage 4 kidney cancer and am unable to work, and I have 6 children, so money is tight. Taking it to a shop isn't an option, and I generally enjoy working on quality equipment, but I am stumped.